|
First
commercially available recombinant Sulfhydryl Oxidase
 Sulfhydryl
oxidases catalyse the formation of disulfide bridges between thiol
groups. This reaction has many applications in industry like for
example the inactivation of unwanted thiol components and the
specific coating or labelling of free thiol groups, or in
stabilising the protein matrix of bakery products.
The
sulfhydryl oxidase from yeast is the first recombinant enzyme that
can be expressed in large amounts. Specific advantages of this
enzyme are high thermo-stability, oxygen resistance and very
favourable energetic properties. Oxygen
from air is the only necessary substrate for the enzymatic reaction
with thiol groups. The enzyme contains tightly bound FAD as a
cofactor and therefore has a bright yellow colour. Important
properties concerning the application of the enzyme are the
relatively broad pH optimum between pH 6.0 and 10.0 and a
temperature optimum between 30 and 50 degrees C.
We
used genetic engineering to create new variants of the enzyme with
unique properties. These
variants exhibit redox-dependent and reversible colour changes that
offer new applications as a bio-indicator to monitor oxygen, thiol
groups or redox reactions. The unique electrochemical properties are
essential for future applications in chiptechnology or nanoscience. X-zyme
holds the international patent for the enzymes from yeast and
plants. X-Zyme
Biotechnology also provides access to unique libraries of
oxidoreductases variants and conducts the screening of these
libraries for the selection of biocatalysts with desired properties.
Because all of them are available as recombinant enzymes, we can
produce them in a very short time in large amounts and a quite high
quality.
 |
 |
|
3D
model of the yeast sulfhydryl oxidase
A
four-helix bundle forms a unique FAD
binding
site. Cysteines are displayed in red. |
Colour
of highly purified recombinant
sulfhydryl oxidase. (mutant C30S: black; mutant
C130S: orange; wild-type: yellow) |
|